Is it a MULTI YEAR contract ? If so and you really want to rent it. Irragated is hard to come by. Possibly see if he would reduce rent for damages next year or two for damages. Then put up a HOT wire . He may be mad because he couldnt get the cows out and you didnt come and help. Your lucky to find them in a corn field without driving through it and doing more damage. DId he graze the stock fields after harvest? Would be hard to adjust now. Should have been handled sooner. My insurance has covered damages his should, if he has any. If you rent it again make him get liability for next time it happens.